I wasn't told to stop my metformin and have a ct with contrast in morning, should i rebook and inquire or go and not worry about it.

Get kidney Fx Check: Metformin is primarily metabolized through the kidneys, so as long as your Diabetes is not profoundly out of control where you should be on another medication while getting the CT with contrast (which also goes through your kidneys), then you should talk with the ordering Doctor and hold the metformin, get the CT Off the meds, and then restart a day or so later after the CT dye.